Apparatus and methods are provided for detecting and monitoring proteolysis of protein matrices such as fibrin clots, extracellular matrix and collagen matrix. The apparatus and methods involve in general the measurement of diffusion-limited electrochemical currents generated by an electroactive species or elactomer in a synthetic protein matrix. The apparatus and methods are applied in various embodiments to detect and monitor the proteolytic activities of a sample, and more specifically fibrinolytic activities and collagenase activities of a sample. The apparatus and methods are utilized generally in the monitoring and diagnostics of cardiovascular, cerebralvascular, and oncology conditions.